Long term effect of water on resin

[Ropey Norton]

I'm sculpting a large hippo to be placed in fresh pond water. Does anyone know the long term effect of water on cold cast bronze resin? How long would it last and what is the best type of resin to use?

[Merlion]

I don't have the direct experience. But I think it may be worth the higher cost to have it casted in bronze instead of unpainted cold cast bronze resin.

[fused]

I would talk directly with the manufacturer of any resin you choose. Besides the constant contact with water, you should also be concerned with the effects sunlight might have on the resin as well. Find out from the source what it's specifications are and all potential maintenance problems.

[Bill Harsey]

uv radiation might be a concern too.

Edited to add: because almost all polymers and resins I know of are subject to uv radiation (sunlight) breakdown at some point. If someone knows different, please advise.

Edited one last time: I'd go with fused advise and then I'm going to go do pushups in sharp steel grit for failing to read his previous post carefully and see that he already addressed this concern..

[Daniel]

Speaking from my troubles with a current project, DON'T use epoxy resin unless you want your sculpture to turn very yellow very quickly out in the sun. Regarding the effects of water, I would concur with the above advice to consult with the resin manufacturer's tech people. I would also agree with Merlion that if you want to create an enduring piece you might consider forking over the extra dough to have it cast in real bronze. Thousands of years from now people might still be able to admire your hippo creation.

[Merlion]

Thousands of years from now people might still be able to admire your hippo creation.
Don't have to think about thousands of years. Even for outdoor sculptures expected to last well in water for more than 10 years, I think it is already worth it to go for bronze instead of resin.

[Daniel]

Just food for thought, though, fiberglass is a very common material for boat building.

[Bill Harsey]

Just food for thought, though, fiberglass is a very common material for boat building.
and...

[Merlion]

Just food for thought, though, fiberglass is a very common material for boat building.
I was aware of this when I made my earier comments. These boats are well painted. And I think they get repainted from time to time. I think Ropey who started this thread was asking about cold cast bronze resin, which means it is not painted in order to show off the embedded bronze powder.

[Daniel]

Actually, the outer surface of most fiberglass boats is pigmented gel-coat, which is resin with fillers, not "paint". It is a part of the composite laminate cast into the mold. Your cold-cast bronze could be made with a clear gel-coat with bronze powder filler. Not that much different from the boat, actually. The same materials are being used with the exception of the bronze powder. And by the way, I'm not trying to tout the benefits of cold-cast bronze just so you don't get the wrong idea. I just thought I would bring up the fact that fiberglass boats that are in water 24/7 survive just fine, as a response to the concern about the adverse effects of water on cold-cast bronze.

p.s. millions of gel-coat and fiberglass shower stalls, jacuzzis, etc. around the world stand up well for years. The dome-shaped front section of military submarines are even fiberglass (to allow sonar penetration) and survive the severe pressures of the bottom of the ocean. Be sure to use marine-grade resin in your sculpture.

[Bill Harsey]

Actually, the outer surface of most fiberglass boats is pigmented gel-coat, which is resin with fillers, not "paint". Your cold-cast bronze could be made with a clear gel-coat with bronze powder filler. Not that much different from the boat, actually. The same materials are being used with the exception of the bronze powder. And by the way, I'm not trying to tout the benefits of cold-cast bronze just so you don't get the wrong idea. I just thought I would bring up the fact that fiberglass boats that are in water 24/7 survive just fine, as a response to the concern about the adverse effects of water on cold-cast bronze.
There seems to be some information (via Google) on uv resistant coatings used especially for this application.

Ropey Norton is in London, he doesn't have to worry about the sun ruining any work there. :D

[anton]

hi all i know i know but go to smooth-om.com and have a look at there tech pages on resin's and then at there tech page's on uv resin i have done a mix of gellcoat and bronze powerder it come up dull i still need to mix in more bronze powerder it the mix ? as for water and resin pool's are made of resin? and they holled up to water well and has cloren and pool aset in it ????
some thing to think abote!!!!!!!
anton

[Tyrone]

hey there

well, my lecturer and i successfully cast a two metre tall figure from a silicone rubber mold in cold- cast bronze, and so, i hope that my advice can help you out.. we applied an initial layer of gel- coat mixed with bronze powder. thereafter we used general purpose "runny" resin and glass- fibre to bulid it up. once cured, removed from mold, fettled etc etc, we buffed it up to a very high shine. its quite labour- intensive, but the rewards are great. it is an almost perfect simulation of actual bronze, but light enough for one man to lift and move around.
anyway, one of these pieces is now standing on the water's edge in the middle of our city. now, if you polish the surface with a wax, this would repel the water and so protect the surface "skin" of your cast - and only for as long as the wax layer remains. if you go this way, be prepared to regularly maintain this surface at least once a month with a fresh layer of wax. however, if you do not apply wax to the bronzed surface of your piece, in the same way that an actual bronze piece would change colour (as with patinations, etc) this cold- cast bronze will also change colour as the fine powdered bronze close to the surface will be exposed to the natural elements of the environment, and so expect a slight change. if your piece is properly sealed where it would sit in the water, there should be no problems.
hope this helps, and good luck
Tyrone

[Lesabre]

I work pretty extensively with cold cast products and concur with the view that direct discussions with resin manufacturers would be a great start. One thing not mentioned yet is the potential impact that submerging a large resin item into a fresh water pond might be. Resin is catylized with methyl ethyl ketone which is very toxic and the resin itself is fairly nasty as well. If this pond connects to a local aquafer and these various chemicals start to leach as the piece ages in the water there could some unfortunate environmental issues. It might be a good idea to look into your liability in this situation.
Cast bronze is more expensive but you could be saving yourself a lot of grief and potential problems down the road by utilizing it.